Anastomosis device and method

ABSTRACT

An apparatus for treating a heart includes a housing member having a plurality of elongate channels defined therein and is movable between a first collapsed position and a second expanded position. A tissue attachment member is positioned in each channel. In one aspect, the apparatus is adapted for performing an anastomosis and includes a housing member having a plurality of elongate channels defined therein and which is movable between a fist collapsed position and a second expanded position. A surgical clip is positioned in each channel. A clip deployment mechanism projects the clips from their respective housings and a registration member approximates and aligns the first and second tubular structures. In a further aspect, helical barbs are movably affixed within sleeves formed on a sheetg of biocompatible material adapted for placement within a heart ventricle. Methods for treating a heart and reducing the volume of a heart ventricle are also provided. In a still further aspect, helical barbs provide attachment for patches for closure of a wound site or for suturing of a site needing closure. In yet another aspect of the invention, the helical barbs provide an attachment regine for implantable devices, as a well as a means to deliver medically efficacious materials to chosen sites with secure means. The helical device of the present invention further serves as a stent.

FIELD OF THE INVENTION

The present invention relates generally to the art of surgicalinstruments and methods and, in particular, to an improved apparatus andmethod for performing an anastomosis or surgical connection betweentubular structures or vessels. The present invention finds particularapplication in the anastomotic joining of vascular tissue for thepurpose of bypassing an occluded or diseased section of a blood vessel,such as a coronary artery, and will be described with particularreference thereto. However, it will be recognized that the presentinvention is amenable to anastomosis in general. The present inventionfurther has broader applications in many different environments, such assecuring patches for the noninvasive correction of intestinalperforations, deep hole wound closures, and others. The presentinvention has still further applications in the medical field, such asin affixing medical devices to tissues, attaching biologicalmicroelectromechanical systems (MEMS), drug delivery, sensor attachmentand uses as a stent.

BACKGROUND OF THE INVENTION

Commonly in coronary artery bypass graft (CABG) procedures, one or moregraft vessels are hand sutured into place between a blood source, suchas the aorta, and a target coronary artery, such as the left anteriordescending artery. Most CABG procedures are accomplished by opening thechest wall to gain access to the coronary vessels. Through the use ofheart-lung bypass machines and cardioplegia to protect the heart, theheart is stopped to enable the surgeon to perform the precisemanipulations required to hand suture the tiny, delicate vessels.

Although bypass grafting has been highly successful, there exists a needfor minimally invasive techniques for bypassing the coronary arteriesand for performing the anastomosis on a beating heart. Minimallyinvasive procedures have been developed in which the bypass is performedthrough a small incision in the chest wall. A number of techniques arealso known for reducing the effects of vessel movement when performingthe suturing on a beating heart. However, techniques that dampen orisolate the translation of movement from the beating heart to the arterycan damage the vessel or cause myocardial injury.

Additionally, techniques are also known which rely on cooling thepatient to slow the rate of the beating heart. This allows the surgeonto place the sutures between heartbeats. However, such techniques canincrease the time it takes to perform the procedure and do not eliminatethe movement of the artery.

Consequently, there is a need for a catheter-based, mechanical methodfor automating an anastomosis, i.e. the surgical connection of tubular.structures. Such an apparatus and method do not require hand suturingand provides for a leak-free connection between vesicles.

Separate and apart from the above, left ventricular enlargement or“remodeling” is a pathologic, progressive process that can followmyocardial infarction and other cardiomyopathies. The infarcted regionbecomes noncontractile and akinetic or dyskinetic, thus reducing thevolume output of the heart. As a result, left ventricular enlargementoccurs to restore or maintain output of oxygenated blood to the body.This dilation has the deleterious effect, however, of imposing an extraworkload on the remaining healthy heart tissue and increasing walltension, which, in turn, stimulates hypertrophy. With damage to themyocardium, however, these increased requirements placed on thecontracting myocardium may be of such an extent that cardiac outputrequirements are not met, and the heart continues to dilateprogressively. This cycle can lead to congestive heart failure, which isa major cause of death and disability in the United States.

Additionally, postinfarction left ventricular aneurysm is an extremeexample of adverse left ventricular remodeling. Such an aneurysm leadsto deterioration of cardiac functions and symptoms of congestive heartfailure.

In order to address these difficulties, it is known to place a patchwithin an enlarged left ventricle to reduce the volume, improve ejectionfraction, reduce wall stress, and otherwise to restore the ventricle toa more physiologic morphology and function. Typically, these procedureshave required incising and introducing the patch through the heart walland hand suturing the patch in place. Thus, there also exists a need foran endoventricular patch plasty apparatus and method that iscatheter-based and that does not require hand suturing.

The present invention contemplates new and improved catheter-basedtissue attachment devices and non-invasive methods which overcome theabove-referenced problems and others.

SUMMARY OF THE INVENTION

In a first aspect of the present invention, a catheter-based apparatusfor treating a heart includes a housing member having a plurality ofelongate channels defined therein and which is movable between a firstcollapsed position and a second expanded position. A tissue attachmentmember is positioned in each channel.

In a second aspect of the present invention, a device for performing ananastomosis between a first tubular structure and a second tubularstructure includes a housing member having a plurality of elongatechannels defined therein and which is movable between a first collapsedposition and a second expanded position. A surgical clip is positionedin each channel. A clip deployment mechanism projects the clips fromtheir respective housings and a registration member approximates andaligns the first and second tubular structures.

In a third aspect, an apparatus for altering the morphology of a heartincludes a sheet of biocompatible material adapted for placement withina ventricle and having a plurality of generally rigid elongate sleevesattached thereto. The sleeves are spaced apart and extend radially. Asurgical barb is movably secured within each sleeve. The barb movesbetween a first position in which the barb is constrained within itsrespective sleeve and a second position adapted for securing the sheetto an interior wall of the heart.

For example, this aspect of the present invention can be used for thetreatment of the enlargement of the left ventricle that results from avariety of heart ailments. This condition leads to congestive heartfailure with a median population mortality of 5 years. The presentinvention can be utilized to reduce the volume of the left ventricle inorder to reduce stress in the myocardium and increase the ejectionfraction of the heart. In utilizing this aspect, a diaphragm can bedeployed by a catheter into the left ventricle of the heart, creatingtwo separate chambers and reducing the overall volume.

In a fourth aspect, a method for treating a heart includes forming afirst elongate incision in a vascular graft and a second elongateincision in a target coronary artery of the heart to define ananastomotic site. A catheter is inserted into the graft and theincisions in the graft and the target artery are aligned. A registrationdevice is passed from the catheter through the first and secondincisions, into the target artery, and a tissue-fastening device ispassed from the catheter into graft. The tissue fastening apparatusincludes a housing member having a plurality of elongate channelsdefined therein, the housing member being movable between a firstcollapsed position and a second expanded position, a surgical clippositioned in each channel, and a clip deployment mechanism forprojecting the clips from their respective channels. The graft andtarget artery are approximated with the registration device and theclips are deployed from their respective channels. The housing member,clip deployment mechanism, registration device, and catheter are thenremoved from the anastomotic site.

In a fifth aspect of the present invention, a method for reducing thevolume of a heart ventricle includes introducing a patch into theventricle and securing the patch to an interior wall of the ventricleusing barbs. The patch includes a sheet of biocompatible materialadapted for placement within a ventricle, a plurality of generallyrigid, elongate, and radially extending sleeves attached to the sheet,and a surgical barb movably secured within each sleeve.

The present invention is adapted to minimally invasive techniques, thusreducing the trauma, risks, recovery time, and pain that accompanycurrent open-chest techniques.

Still further advantages and benefits of the present invention willbecome apparent to those of ordinary skill in the art upon reading andunderstanding the following detailed description of the preferredembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take form in various components and arrangements ofcomponents, and in various steps and arrangements of steps. Thedrawings, in which like reference numerals denote like componentsthroughout the several views, are only for purposes of illustratingpreferred embodiments and are not to be construed as limiting theinvention.

FIG. 1 illustrates exemplary tubular structures with aligned incisionsfor anastomosis in accordance with the present invention.

FIG. 2 is a longitudinal cross-sectional view of portions of the graftand target vessels and shows a catheter device for intraluminallycarrying and delivering the anastomosis device of the present invention.

FIG. 3 is a longitudinal cross-sectional view of the catheter sheathingidentified in FIG. 2 and shows the housing storing the clips and theregistration device.

FIG. 4 is a cross-sectional view taken along the lines 4-4 of FIG. 3.

FIG. 5 is a longitudinal cross-sectional view of the vessels and showsthe housing storing the clips and the registration device deployed toapproximate and align the incisions.

FIG. 6 is a view similar to that of FIG. 5, illustrating the position ofthe clips in a partially deployed state.

FIG. 7A illustrates the removal of the registration device and catheterafter the clips are in place.

FIGS. 7B and 7C illustrate the preferred helical shape of the fasteningclips, helical barbs and helical devices of FIGS. 7-11 when in use. FIG.7B is a view of the helical shape from one side, and FIG. 7C is a sideview of FIG. 7B.

FIG. 8 is a perspective sectional view of the completed anastomosis.

FIGS. 9 and 10 illustrate an alternative embodiment of the presentinvention in which the clips remain attached to the housing.

FIG. 11 illustratively shows a device attached in accordance with thepresent invention.

FIG. 12 illustrates the use of the helical device of the presentinvention as a stent.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to the drawings, wherein the showings are for purposes ofillustrating the preferred embodiments of the invention only and not forlimiting the same, FIG. 1 shows an anastomotic site 10 involving a firstvessel such as an artery 12 and a second vessel such as a graft 14. Theartery 12 may be, for example, a coronary artery containing a stenosis16 and the graft 14 may be, for example, a harvested vein or artery, ora synthetic vascular graft material such as expandedpolytetrafluoroethylene (ePTFE) or the like. The location of one or moreanastomotic sites are selected to bypass the blockage 16 and restore aphysiologic blood flow to the areas downstream therefrom.

A longitudinal incision 18 is defined in the artery 12 at the intendedanastomotic site 10, for example, by surgically exposing or accessingthe artery and cutting. Alternatively, a blade or other means forforming the incision 18 can be advanced to the anastomotic site 10intraluminally in a catheter via the artery 12 for forming the incision18 percutaneously. A corresponding incision 22 is also defined in thegraft 14.

The graft vessel 14 can be a harvested blood vessel segment such as thesaphenous vein or interior mammary artery (IMA), or, a syntheticvascular graft material. Alternatively, the graft 14 can be a nearbyvessel anastomosed to the artery 12 in situ. In still other embodiments,the graft 14 may be a vessel, such as the IMA, that is harvested at oneend only and left attached at the end distal to the anastomotic site.

Referring now to FIG. 2, there appears in the graft 14 a catheter 20having an end 24 distal to the operator (not shown). The catheter 20defines a channel through which the anastomosis device of the presentinvention is passed.

In operation, the graft 14 and artery 12 are placed in longitudinalalignment so that the respective incisions 22 and 18 are substantiallyin aligned, facing relation. The catheter is then advanced within thelumen of the graft 14 until the distal end 24 is aligned with theincision 22.

FIGS. 3 and 4 illustrate an anastomosis device 30 of the presentinvention folded or collapsed and retained within the catheter 20. Thedevice 30 includes a registration means 32, such as an inflatablechamber, and a main housing 34 storing a plurality of fastening clips36.

The main housing 34 includes foldable or flexible walls 38 and hollowrigid or semirigid elongate clip housing members or stays 40, eitherdefined therein or secured thereto, each defining a channel andretaining a clip 36. The flexible walls 38 are formed of a sheetmaterial, such as Dacron polyester, polytetrafluoroethylene, and thelike such as GORE-TEX polytetrafluoroethylene, or other FDA class 3materials for implantation. The elongate clips 36 are formed from ashape memory alloy (SMA) or superelastic alloy that is FDA class 3approved for implantation, such as NITINOL or TiNi, which arenickel-titanium based alloys, or alike materials.

The clips are formed of a shape memory or superelastic material, e.g., anickel-titanium alloy, for example, in the form of a wire having aneedle-like point 37 (see FIG. 6) on one leading end. The shape of eachclip 36 is “set” or “trained” to a curved shape in a known manner. Forexample, the wire can be constrained in a circular shape on a mandreland heat-treated.

The shape-memory or superelastic clips 36 are readily deformable and areplaced in the elongate channels 40, which constrain the clips intemporary, straightened shape. In a particularly preferred embodiment,the elongate channels have a slightly elliptical or oval cross-sectionalshape. Since the pre-shaped clips have a lower stress when the plane ofthe circle defined by the unrestrained clip is aligned with the longaxis of the ellipse, the clip inherently maintains the desired alignmentin the channel. Thus, the orientation of the channels is selected tocontrol the direction and orientation of the clips 36 when they aredeployed. The specific preset curvature of the clips is selected tocontrol the bite of the clip as it is deployed. Also, the alloycomposition and/or the heat-treatment conditions (temperature, time) canbe adjusted to impart the desired shape-memory or superelasticcharacteristics.

In certain embodiments, a nickel-titanium alloy designed to takeadvantage of the superelastic effect, i.e., having an active A_(f)temperature below the use temperature (e.g., body temperature), isemployed as the clip 36 material. Such clips are extremely flexible andabsorb the strain energy of being constrained in the clip housingchannels 40. The strain energy is released as the applied strain isremoved, i.e., when the clips are deployed from the channels 40,reverting to the helical shape. In this regard, the clip housings areelliptically shaped tubes that elastically constrain the previouslyshaped clips. The elliptical shape of the housing allows the directionof the deployed clip to be defined—the curvature of the clip will alignitself with the major axis of the elliptical ID, which minimizes thestrain in the clip. The clip may be deployed by mechanically ejectionfrom the housing, for example, by pushing a wire (located behind theclip) into the housing. In applications where the clip remains attachedto the housing (e.g., barbed attachment of patches) the clip and thepusher wire are preferably one piece (not separated) and only thehelical end is exposed during deployment.

The preferred helical shape of the clips and barbs of the presentinvention is shown in FIGS. 7B and 7C, and is defined so that the tips68 (also specifically identified herein as 37 and 58), of the curvedclips and barbs are extended past each other sufficiently to assure thatthe clip remains in attachment to the desired tissue for the applicationof interest. The amount the tips extend beyond each other may varydepending on the medical application, the strength of the superelasticor SMA material used, the load placed on the material, the tissue inwhich it is deployed and its resistance to penetration. The preferredamount is thus variable within the range that permits the helical barbto be deployed to assure attachment and avoid detachment upon loadingwhich might cause separation of the tips so that they no longer extendpast each other. When extended beyond each other, the clips and barbsassure that there is always a portion of the clip in contact with tissuesought to which the clip or barb is to be secured. More than onerotation of the helix forming the helical shape is required and,typically, no more than two rotations is needed.

In other embodiments, a shape memory alloy, such as a thermallyactivated shape memory form of NITINOL, is employed. The clips arepliable when chilled and are readily maintained in a straightened shapein the housing channels 40. An alloy having a transformation temperatureat or near body temperature is selected so that the clips will return totheir circular shape when warmed to body temperature. The clipdeployment is actuated by any mechanism that could exert an appropriateforce on the pusher wife. For example, a toggle linkage, a pneumatic orhydraulic piston, or a shape memory spring can be used to actuate clipdeployment.

Referring now to FIG. 5, the anastomosis device 30 of the presentinvention is passed through the distal end 24 of the catheter 20 and isinserted through the incision 22 in the graft vessel 14 and inflated,e.g., via a syringe 50 attached at the distal end of the catheter andcontrolled by the operator. Other pneumatic devices for inflating thedevice 30 are also contemplated.

Preferably, the registration member 32 is a pneumatic chamber that, wheninflated, serves to approximate and register the vessels to be. joined.The registration member 32, which is a balloon in the depictedembodiment, extends through the incision 18 and into the artery 12. Theballoon 32 is shown inflated, bringing the vessels 12 and 14 together incooperation with the housing 34 storing the clips 36. A boundary 35between the inflatable vessels 32 and 34 serves to register the clips,while the inflated chambers 32 and 34 push the tissues between thevessels together. The boundary 35 may be, for example, a constrictedregion formed therein, an annular band, or the like. By providing properalignment of the incisions, healing is facilitated. When a nonlivinggraft material 14 is used, the opening 22 is preferably treated to allowlimited tissue ingrowth.

In an alternative embodiment (not shown), the balloon 32 is replacedwith a series of mechanical fingers located between the clips, thatclose to clasp the tissues between the vessels, thereby accomplishingboth approximation and registration functions.

Referring now to FIG. 6, the clips 36 are deployed and the needle-likepoints 37 puncture and curl through the adjacent tissues of the graft 14and artery 12 to form a strong mechanical bond therebetween. In FIGS. 7and 8, the completed anastomosis is shown. The graft vessel 14 is shownin partial cutaway to illustrate the removal of the catheter 20, cliphousing 34, and registration member 32.

In an alternative embodiment, the clips are not completely deployed fromtheir respective housings, and one end of the clip remains attached tothe housing. This barb attachment allows many different devices to besecurely attached to various types of tissue. Although many otherapplications are appropriate, a particular application for the subjectapparatus is endoventricular left ventricular (LV) volume reductionfollowing physiologic LV remodeling (enlargement), e.g., followingmyocardial infarction and other heart ailments. Other applicationsinclude, for example, wound closure, attachment of biologicalmicroelectromechanical (MEMS). devices, and attaching patches for thenoninvasive correction of intestinal perforations.

Referring now to FIGS. 9 and 10, there is shown an attachment device 50which comprises a patch or diaphragm 52 supported by radiallyspaced-apart and generally rigid or semirigid hollow ribs or stays 54.

The stays 54 are hollow and each houses a barb 56. The device 50 assumesa folded or collapsed position by parallel alignment of the stays 54 anda corresponding folding of the patch material 52 for introduction intothe ventricle via a catheter 60 defining a channel though which thedevice 50 is passed.

The patch 52 comprises a sheet material, which is circular, or, morepreferably, oval or elliptical in shape. The patch may be formed from,for example, Dacron polyester, GORE-TEX polytetrafluoroethylene, orother FDA class 3 materials for implantation, which could beadditionally treated with thromboses modulating agents or otherprescriptions to allow controlled tissue ingrowth. Alternatively, thediaphragm can be formed of fixed mammalian tissue, such as bovine orporcine pericardium, autologous pericardium, etc.

The barbs 56 include a tissue-piercing pointed distal end 58 extendingin a radially outward direction. The barbs are secured within therespective housings at an end opposite the pointed ends 58. Limitedmovement of the barb in the axial direction is optionally provided toextend the barbs for deployment.

The barbs 56 are formed of a nickel-titanium alloy having superelasticand/or thermally activated shape memory characteristics. When the clipsare made of a superelastic alloy, the barbs are constrained in astraightened shape by the housings 54. When deployed, the barbs 56,e.g., by mechanically pushing the barbs outwardly a short distance fromtheir respective housings, resume their helical shape, puncturing andcurling into the adjacent tissue to form a strong mechanical connection.Similarly, a shape memory alloy which becomes activated at or belowbody-temperature can be used in similar fashion, in which case thethermally activated alloy is cooled to increase its flexibility andreturns to the trained helical shape upon warming within the body. Eachbarb may be ejected as described above, for example, using a pusher wireurging, or more preferably, attached to the proximal end of the barb,and so forth.

In an especially preferred embodiment, the barbs are deployedsequentially to generate a torque that helps to assure contact of thediaphragm with the adjacent tissue 62, such as an inner ventricularsurface. The sequential deployment is illustrated in FIG. 10. A firstbarb 56 a having a pointed end 58 a extends from within housing 54 a inits fully deployed position and a second barb 56 b having a pointed end58 b is just starting to project into the myocardium 62. The barbs aresequentially deployed (counterclockwise in the depicted illustration)until all of the barbs have been deployed. The cross-sectional shape ofthe sleeves 54 controls the orientation of the barbs. As describedabove, the barb housings 54 have an oval or other cross-sectional shapeproviding a preferred orientation of the barbs 58.

As may be further understood from the discussion above, the presentinvention has further, broader application to a wide variety of medicalenvironments within the body to secure patches or to suture a siterequiring closure, such as needed for wound repair, deep hole woundclosures, intestinal perforations, incision sites and other needs whereclosure or suturing opposing tissues at a site are required.

The method for repairing tissue at a site requiring closure includesfirst introducing a patch into the body, preferably through anon-invasive catheter procedure. Such procedures may be initiatedthrough vessels of various types, or initiated through the body cavity.The catheter would carry a patch or sheet of biologically compatiblematerial, adapted for the specific tissue targeted for repair. Materialsappropriate for closure of different sites in the body are known in theart for exposure to the environments in which they must function, andthose discussed above are illustrative for the cardiovascularenvironment.

As with the illustrative device shown in FIGS. 9 and 10, the sheet ofbiocompatible material preferably includes a plurality of generallyrigid elongate sleeves. Such sleeves may either be present in the sheetor attached to the sheet, so long as they can function to permitmovement of a surgical barb therefrom. The sleeves are positioned toextend the sheet of biocompatible material into a configuration suitableto enclose the selected portion of the body as a patch.

The patch is then secured over the portion requiring closure byextending said barbs to a helical position so that the barbs engagetissue surrounding the portion requiring closure. The barbs are made ofmaterials as described above, such as superelastic, shape memorymaterials, or like materials, and are preferably extendable using amechanical device to push them partially from the sleeves, in a mannersimilar to that described above, to deploy to a helical position. It isunderstood, however that the barbs may be activated assume a helicalshape in other ways, including electrical heating, ultrasonic activationfrom a remote source, and timing devices. In accordance with theinvention, the barbs are extended to a helical shape to provide forattachment of the patch without further suturing, and enable the patchto be attached from one side of the site, without further intrusion intothe targeted site.

The present invention further provides for the suturing of tissue at asite requiring closure using the helical barbs. The method againpreferably involves the introduction of elongate sleeves, preferablythrough a catheter or other non-invasive tool. Surgical barbs aremovably secured within each sleeve, and are spaced apart as desired forthe suturing procedure desired. In the extended position, the surgicalbarbs will return to a helical shape, whether activated by temperature,electrical current, external power supply or a timer circuit to triggerconditions for shape change.

In the suturing application, the sleeves with barbs may be positioned atthe site requiring closure one at a time, or in groups, or as a clusterattached to a sheet that deploys them to a desired spacing, whether suchspacing is parallel, radial or in otherwise oriented. After positioningthe sleeve or sleeves into the desired position, the barb is extendedfrom the sleeve into a predefined helical position where the barbengages tissue on opposing tissues at the site requiring closure andserves as a suture. The helical barb is preferably then fully expelledfrom the sleeve, and the sleeve removed from the body or used to deliverconsecutive barbs. When functioning as a remotely positioned suture, thehelical barb of the present invention has the distinct advantage ofproviding secure connection from just one side of a tissue, withoutneeding access to the opposing side of the tissue to achieve a secureattachment. It further serves both as the needle and the suture, and maybe made of materials as discussed herein.

In a still further application in the medical field, the presentinvention encompasses a helical barb device that is suitable foraffixing medical devices, generally, to tissues. While illustrativelyshown in the process of attaching a diagram in FIGS. 9 and 10 orsecuring a graft to an artery in FIGS. 1 to 6, the present invention mayfurther be used to attach biological microelectromechanical systems(MEMS), sensors, filters, batteries or other implantable devices 70 asshown representatively in FIG. 11. Again, the helical barb has thedistinct advantage of providing secure connection from one side of atissue, without needing access to the opposing side of the tissue toachieve a secure attachment. It further serves both as the needle andthe suture, and may be made of materials as discussed herein.

Where the helical barb affixes medical devices within the body, it maybe deployed in a manner similar to that described above from a sleeveattached to a larger implantable device, where a portion of the barbremains attached within the sleeve. Alternatively, the sleeve might alsoserve as the device to carry a device, whose inner and outer surface areexposed to the targeted tissues upon deployment of the helical barb.

Where micro and nanotechnologies are being inserted into the body, thehelical barb itself may be the carrier for small devices attached to thesurface of the barb. In this configuration, the micro or nano devicesare appropriately positioned on the barb when it is in its first,non-deployed position, such as an elongated position in a sleeve, sothat in its second position penetrating and attaching to tissue, thedevices would be presented to the tissue without damage, and in aposition where they function as desired. The devices so implanted arecontemplated to monitor or measure biological conditions, manufacture ordeliver medically efficacious materials, or perform other desired devicefunctions. Where the helical barb serves as a carrier for devices, it ispreferred that they be deployed in a manner similar to that describedabove for a sutures, separating from the delivery mechanism.

In its application to attach a device to tissue in a medical procedure,the helical barb functions to connect a man-made, preferablybiologically compatible material to a biological material, in contrastto the suturing of two biological materials. By way of example and notlimitation, devices which may be attached using the helical barb of thepresent invention include blood pressure transducers, glucose monitors,fluid flow sensors to detect bleeding at operative sites, leakinganeurysms, or local fluid build-up.

The provision of a simple helical barb means to deliver a MEMs device,or other nano or micro technology makes possible the dream of drugdelivery at the site of need using a device which will remain in placewhere chosen. The potential to use such devices as small local drugfactories, or as drug dispensing agents from which drugs can disperseover time is known in the art. The helical barb device of the presentinvention provides a secure means of attachment, whether serving as anattachment means for a larger device or as the carrier for very smalldrug delivery devices.

It is further contemplated in the drug delivery application of thepresent invention that the material of the helical barb may be hollow,and serve as a carrier for drugs. The hollow ends may be plugged withbiodegradable material, or simply be plugged by the delivery mechanismso that once fully deployed and released at least one end of the helicalbarb becomes exposed to deliver treatment materials as the deliverydevice retracts. Alternatively, the helical barb may be coated withmedicament, so that it is delivered directly to the tissue upon thepenetration and attachment of the barb.

It is still further contemplated that the helical barb of the presentinvention may include biodegradable materials whose period of integrityis designed to last as long as the drug delivery device remainsoperable, or as long as timed release of drugs from a device lasts,after which time the helical barb device is designed to fail so that thedevice may be easily released and either expelled or retrieved from thebody.

Medically efficacious materials that may be delivered include drugs,hormones, small molecules, proteins, genetic materials, radioactivematerials, markers, biological agents and other treatment materials. Byway of example and not limitation, human growth factor Veg-F might bedelivered using the helical barb or in combination with a MEMs or otherdevices to treat coronary artery blockage, promote angiogenisis, orprovide cardiac drug delivery without the need for repeated hearthcatheterizations. Use in targeted high blood flow areas can also providefor enhanced treatment opportunities. Radioisotopes and chemotherapeuticagents may also be placed and positively attached with the helical barbof the present invention directly at the site of tumors, providinglonger-term drug delivery.

In a further drug delivery application, the helical barb of the presentinvention (in a first elongated position), an implantable device, or athe sleeve may be initially implanted at a desired biological locationby coating at least a portion thereof with a biological/proteinattachment material targeting the desired site. Numerous targetingproteins are discussed in the art for different functional organs. Inone configuration, the helical barb may be treated in its first elongateposition, ingested or implanted, separately or in combination with adevice, and once the device or barb adheres chemically to the targetedportion of the body, the attachment may then be made more permanent bydelayed deployment of the helical barbs.

The helical barbs may be deployed in such an application, as with theother applications of the present invention discussed herein, throughtimed action or remote signal, such as an ultrasonic signal or othertrigger, electrical current, temperature, or timed release of the barbsfrom a device.

In addition to serving as a helical barb for attachment, the helicaldevice of the present invention may serve to lodge itself in a vessel orother generally tubular structure or opening by deployment from a firstposition, preferably by means of a catheter, to a second helicalposition where the helical device relies on its radius of curvature toexpand to a size at which it lodges in the vessel, or other biologicalstructure, opening, duct or orifice.

Such a vessel, structure, opening or duct would have an average radiusless than that of the helical device. As shown in FIG. 12, once in thisposition, the helical device may serve as a stent 76, as a carrier for adevice 70, such as a sensor 74 or MEMs 72 as described above, or as adrug delivery vehicle as described above.

When serving as a stent, the helical device may be configured to havemany loops, as shown in FIG. 12 rather than the preferred design of thehelical barb shown in FIG. 7B and described above. Further, in a stent,MEMs devices may be embedded in the superelastic or shape memorymaterial, or spaced on the surface for monitoring or measuring ofbiological or treatment parameters or for drug delivery, or combinationsthereof.

The helical barbs, fastening clips and helical devices of the presentinvention are preferably formed either of a shape memory alloy (SMA) ora superelastic alloy that is FDA class 3 approved for implantation, suchas NITINOL or TiNi, which are nickel-titanium based alloys, or alikematerials, and are formed as a wire with diameters down to 25 microns,and have a needle-like point on at least one end. Some polymers,including but not limited to starch-based polymers, are also known whichexhibit superelastic properties desirable for application in accordancewith the various aspects of the invention described herein. In addition,the ends of the barbs may include end treatments such as barbs and teeththat provide additional anchoring capability for the barbs, devices,sutures and attachments described herein.

Use of SMA materials is contemplated for the above applications. Amongthe opportunities provided by such materials is the design of theshape-memory transition temperature. so that the natural hysteresisbetween phases would advantageously be set to enable activation of thematerial to cause shape change by electrical means. Specifically, thehigh transition to austentite would be just above body temperature. Anelectric current provide or induced in an adjacent or attached devicewould provide heat for the shape memory triggering once the helical barbwas in position at the desired site for attachment to tissue ordeployment into a helical shape. As long as the lower transition back tomartinsite is below body temperature, the helical barb will hold itsshape, just as with a device prepared for deployment upon exposure tobody temperature.

In addition, the hysteresis of shape memory materials provides theopportunity for removal of devices after placement. If the memory shapeis triggered by a temperature slightly higher than the bodytemperatures, then a return to a temperature slightly lower than bodytemperature, by using catheter supplied cooling, such as cooled fluids,cryogenic probes, cooled heat sinks, heat pipes, thermoelectric or othercooling devices, may provide for easier device removal.

The invention has been described with reference to the preferredembodiment. Obviously, modifications and alterations will occur toothers, upon reading and understanding the proceeding detaileddescription.

It is intended that the invention be construed as including all suchmodifications and alterations insofar as they come within the scope ofthe appended claims or the equivalents thereof.

1. A method for delivering a medical treatment to a living organismcomprising: providing at least one attachment device; deploying at leastone said attachment device to a generally helical shape inside with saidliving organism; and producing a medically significant effect related tosaid attachment device.
 2. A method of claim 1, wherein: said attachmentdevice is a helical carrier device including a medically efficacioussubstance; said step of deploying comprises penetrating and attachingsaid helical carrier device to tissue inside said living organism; andsaid step of producing a medically significant effect comprisesdispensing a medically efficacious substance from said helical carrierdevice.
 3. The method of claim 2, wherein said step of providing saidattachment device comprises treating said helical carrier device with asubstance chosen to target a given location in the body; and providingthe helical carrier device in a first position; said step of deployingincludes: ingesting said helical carrier device when in a firstposition; and activating said helical carrier device to deform to asecond helical position and attach to tissue after reaching the targetedlocation in the body.
 4. The method of claim 1, wherein: said step ofproviding an attachment device comprises providing a helical carrierdevice comprised of a material having a first shape permitting insertioninto the body, and a second helical shape having a radius of curvaturethat is larger than the average radial dimension of the biologicalmaterial in which it is disposed, wherein said helical carrier devicefurther includes a medically efficacious substance; said step ofdeploying comprises: inserting said helical carrier device into abiological material in the body while said helical carrier is in a firstposition; and exposing said helical carrier device to conditions causingsaid helical carrier device to assume said second, helical shape largerthan the average radial dimension of the biological material in which itis disposed; and said step of producing a medically significant effectcomprises dispensing a medically efficacious substance from said helicalcarrier device.
 5. The method of claim 1, wherein: said step ofproviding an attachment device comprises providing an elongate materialhaving a first shape suitable for insertion into a tubular biologicalstructure in a living organism; and said step of deploying comprisesexposing said elongate material to conditions causing said elongatematerial to assume a second helical shape having a radius of curvature alarger than the average radial dimension of the biological material inwhich it is disposed.
 6. The method of claim 1, further comprising:providing a registration device; providing a catheter; and providing atissue fastening apparatus, said tissue fastening apparatus including: ahousing member having a plurality of elongate channels defined therein,the housing member being movable between a first collapsed position anda second expanded position, wherein ones of said attachment devices arepositioned in ones of said channels; and an attachment device deploymentmechanism for projecting said attachment devices from their respectivechannels; and wherein said step of deploying comprises: forming a firstelongate incision in a vascular graft; forming a second elongateincision in a target coronary artery of the heart, the first and secondincisions defining an anastomotic site; inserting said catheter into thegraft; aligning the graft and target artery so that the first and secondincisions are in aligned, facing relation; passing said registrationdevice from the catheter through the first and second incisions and intothe target artery; passing said tissue fastening apparatus from thecatheter into the graft: approximating the graft and target artery usingsaid registration device; deploying the attachment devices from theirrespective channels using the attachment device deployment mechanism;and removing the housing member, deployment mechanism, registrationdevice, and catheter from the anastomotic site.
 7. The method of claim1, further comprising: introducing a patch into the ventricle of theheart of said living organism, the patch including: a sheet ofbiocompatible material adapted for placement within a ventricle; aplurality of generally rigid elongate sleeves attached to the sheet, thesleeves spaced apart and extending radially; and wherein said step ofproviding comprises providing ones of said attachment devices in ones ofsaid sleeves, said attachment devices movably disposed within eachsleeve; and said step of deploying comprises securing the patch to aninterior wall of the ventricle by moving said attachment devices intoengagement with said ventricle and into a generally helical shape; saidstep of producing comprises reducing the volume of the ventricle.
 8. Themethod of claim 1, further comprising: introducing a patch into the bodyof said organism, the patch including: a sheet of biocompatible materialadapted for placement within a selected portion of the body; a pluralityof generally rigid elongate sleeves attached to the sheet, the sleevespositioned to extend the sheet of biocompatible material into aconfiguration suitable to enclose a selected portion of the body as apatch, wherein ones of said attachment device are movably disposedwithin ones of said sleeves; and wherein: said step of deployingcomprises extending said attachment devices to a helical position wheresaid attachment devices engage tissue surrounding the selected portionof the body; and said step of producing comprises enclosing saidselected portion of the body with said patch.
 9. The method of claim 1,wherein: said step of providing an attachment device includes: providingat least one generally rigid elongate sleeve wherein ones of saidattachment device are movably secured within each sleeve; said step ofdeploying comprises: positioning said sleeves into a desiredconfiguration in proximity to two portions of tissue in the body of saidorganism; and extending at least one of said attachment devices fromsaid sleeves into a predefined helical position where said attachmentdevices engage said two portions of tissue; said step of producing amedically significant effect comprises connecting said two portions oftissue.
 10. The method of claim 1, wherein: said step of deployingcomprises: deploying said attachment device from a single side of afirst material; and penetrating a second material with said attachmentdevice; and said step of producing a medically significant effectcomprises connecting said first and second materials together.
 11. Themethod of claim 10, wherein: said first material is a medical device andsaid second material is tissue in the body of the organism, whereby amedical device is secured to said tissue by access to only a single sideof the biological material.
 12. The method of claim 1, wherein saidattachment device includes a medical device.
 13. A tissue fasteningapparatus comprising an attachment device deployable from a single sideof a biological material.
 14. The tissue fastening apparatus of claim13, where said attachment device is deployable into a generally helicalshape.
 15. The tissue fastening apparatus of claim 13, wherein theattachment device is formed from a material selected from the groupcomprising: superelastic material, thermally activated shape memorymaterial, and combinations thereof.
 16. The tissue fastening apparatusof claim 13, wherein said attachment device: is ingestible when in afirst position, is treated with a substance chosen to target a givenlocation in the body, and further comprises an activation trigger tocause said attachment device to deform and deploy into the biologicalmaterial after reaching the targeted location in the body.
 17. Thetissue fastening apparatus of claim 13, further including at least onefrom the group of materials having medical significance, comprising: amedicament, a biologically active material, genetic material, proteins,radioactive materials and combinations thereof.
 18. The tissue fasteningapparatus of claim 13, further including a medical device.
 19. Thetissue fastening apparatus of claim 18, wherein said medical deviceincludes one from the group of devices comprising: biologicalmanufacturing devices, pharmaceutical manufacturing devices, electronicdevices, electrical devices, power sources, mechanical devices,micromechanical devices, microelectromechanical devices, monitoringdevices, sampling devices and combinations thereof.
 20. The tissuefastening apparatus of claim 13, wherein: the attachment device iscomprised of a material having a first shape permitting insertion insidethe inner surface of a generally tubular biological material in thebody, and the attachment device is deployable into a second generallyhelical shape having a radius of curvature that is larger than theaverage radial dimension of the generally tubular biological material inwhich it is disposed.
 21. The tissue fastening apparatus of claim 13,further comprising: a housing member having a plurality of elongatechannels defined therein; the housing member being movable between afirst collapsed position and a second expanded position; and a pluralityof said attachment devices, wherein ones of said attachment devices arepositioned in ones of said channels for deployment from a first positionin said channels to a second generally helical position.
 22. The tissuefastening apparatus of claim 21, further comprising: at least onedeployment mechanism for projecting at least one of said attachmentdevices from its respective housing member; and a registration member;whereby said housing member in said first collapsed position may beinserted into a first tubular structure, said registration member mayalign said first and second tubular structures, and said housing memberin said second expanded position may deploy ones of said attachmentdevices to connect the first and second tubular structures.
 23. Thetissue fastening apparatus of claim 22, wherein the attachment devicesare formed from a material selected from a superelastic material and athermally activated shape memory material.
 24. The tissue fasteningapparatus of claim 13, further comprising: a sheet of biocompatiblematerial adapted for placement within a targeted tissue; a plurality ofgenerally rigid elongate sleeves attached to the sheet, the sleevesspaced apart and extending generally radially; and a plurality of saidattachment devices, ones of said attachment devices movably securedwithin ones of said sleeve, movable between a first constrained positionand a second generally helical position such that said sheet is infastened relationship to a surface of the targeted tissue.